A destination to which characters can be written, such as a text file. Unlike a java.io.Writer, a
CharSink is not an open, stateful stream that can be written to and closed. Instead, it
is an immutable supplier of Writer instances.

CharSink provides two kinds of methods:

Methods that return a writer: These methods should return a new,
independent instance each time they are called. The caller is responsible for ensuring that the
returned writer is closed.

Convenience methods: These are implementations of common operations that are
typically implemented by opening a writer using one of the methods in the first category,
doing something and finally closing the writer that was opened.

Opens a new buffered java.io.Writer for writing to this sink. The returned stream is not
required to be a java.io.BufferedWriter in order to allow implementations to simply delegate
to openStream() when the stream returned by that method does not benefit from
additional buffering. This method should return a new, independent writer each time it is
called.

The caller is responsible for ensuring that the returned writer is closed.

Writes the given lines of text to this sink with each line (including the last) terminated with
the operating system's default line separator. This method is equivalent to
writeLines(lines, System.getProperty("line.separator")).